Surgical stapling instrument and associated trigger mechanisms

ABSTRACT

A trigger mechanism for a surgical instrument, particularly, a surgical stapling instrument provides significant mechanical advantages by increasing the length of the firing stroke of the surgical instrument while reducing the degree of movement of the trigger associated with the trigger mechanism. The trigger mechanism also reduces the forces required to actuate the trigger thereby enhancing usability and minimizing operator fatigue.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Division of U.S. patent application Ser. No.16/179,039, filed Nov. 2, 2018, now U.S. Pat. No. 10,993,714 issued May4, 2021, which claims the benefit of U.S. Provisional Patent ApplicationNo. 62/591,735, filed Nov. 28, 2017, the entire disclosure of which isincorporated by reference herein.

TECHNICAL FIELD

The present disclosure generally relates to a surgical instrument and,more particularly, relates to a trigger mechanism for use with astapling instrument and adapted to enhance the mechanical advantage andreduce the firing forces required to actuate the stapling instrument.

BACKGROUND

Stapling instruments for applying staples through compressed livingtissue are commonly used, e.g., for closure of tissue or organs prior totransection, prior to resection, or in an anastomoses, and/or for theocclusion of organs in thoracic and abdominal procedures. In general,stapling instruments include an anvil assembly, a cartridge assembly forsupporting an array of surgical staples, an approximation mechanism forapproximating the anvil and cartridge assemblies, and a firing mechanismfor ejecting the surgical staples from the cartridge assembly. Theapproximation mechanism and the firing mechanism may or may not includedistinct actuators for effecting approximation and firing of thestaples.

Typically, stapling instruments, particularly, mechanically actuated ornon-motorized stapling instruments, require the operator to manipulatethe actuators with a single hand. However, the forces required toapproximate the anvil and cartridge assemblies and/or fire the firingmechanism are relatively substantial in these mechanical systems, whichmay present difficulties to the operator or cause operator fatigue.

SUMMARY

Accordingly, the present disclosure is directed to improvements inmechanically actuated trigger mechanisms for surgical instruments,particularly, surgical stapling instruments. In one exemplaryembodiment, a surgical instrument includes a handle having a handleframe defining a longitudinal handle axis, an elongate member extendingfrom the handle frame, an end effector coupled to the elongate member, athrust member extending through the elongate member and coupled to theend effector and being configured for longitudinal movement to controloperation of the end effector, and a trigger mechanism. The triggermechanism includes a trigger pivotally mounted to the handle frame andconfigured for movement between an initial position and an actuatedposition and a thrust link coupled to the trigger and operativelyengageable with the thrust member. The thrust link extends at a fixedlink angle relative to the longitudinal axis and is longitudinallyadvanceable while maintaining the fixed link angle upon movement of thetrigger from the initial position to the actuated position to causecorresponding advancing movement of the thrust member and operation ofthe end effector. In embodiments, the fixed link angle ranges from 1° to30°.

In another exemplary embodiment, a surgical instrument includes a handlehaving a handle frame defining a longitudinal handle axis, an elongatemember extending from the handle frame, an end effector coupled to theelongate member, a thrust member extending through the elongate memberand coupled to the end effector and being configured for longitudinalmovement to control operation of the end effector, and a triggermechanism. The trigger mechanism includes a trigger pivotally mounted tothe handle frame and configured for movement between an initial positionand an actuated position and a thrust link coupled to the trigger andoperatively engageable with the thrust member. The thrust link definesan elongated slot for reception of a thrust link pin which is mounted tothe trigger. The thrust link is configured to pivot about the thrustlink pin and to longitudinally advance upon movement of the trigger fromthe initial position to the actuated position to cause correspondingadvancing movement of the thrust member and operation of the endeffector.

In embodiments, the elongated slot of the thrust link defines a proximalend and a distal end. The thrust link is positioned adjacent the distalend of the elongated slot when in the initial position of the triggerand configured to traverse the elongated slot for positioning adjacentthe proximal end of the elongated slot upon movement of the trigger tothe actuated position.

In another exemplary embodiment, a surgical instrument includes a handlehaving a handle frame defining a longitudinal handle axis and aninternal guide member with an internal guide surface, an elongate memberextending from the handle frame, an end effector coupled to the elongatemember, a thrust member extending through the elongate member andcoupled to the end effector and configured for longitudinal movement tocontrol operation of the end effector, and a trigger mechanism. Thetrigger mechanism includes a trigger pivotally mounted to the handleframe and configured for movement between an initial position and anactuated position and a thrust link coupled to the trigger. The thrustlink has a forward drive cam engageable with a thrust bar arm of thethrust member and a guide cam engageable with the internal guide surfaceof the guide member of the handle frame. The thrust link is configuredto pivot upon movement of the trigger from the initial position to theactuated position through traversing movement of the guide cam along theinternal guide surface of the guide member to cause correspondingtraversing movement of the forward drive cam of the thrust link alongthe thrust bar arm of the thrust member to cause advancing movement ofthe thrust member through at least a first stage of longitudinalmovement to operate the end effector.

In embodiments, the internal guide surface of the internal guide memberis arranged in oblique relation to the longitudinal handle axis. In someembodiments, the trigger is operable between the initial position, theactuated position and a partial actuated position intermediate theinitial and actuated positions. In certain embodiments, the guide memberof the handle frame is configured such that the internal guide surfaceis released relative to the guide cam of the thrust link upon movementof the trigger beyond the partial actuated position whereby continuedmovement of the trigger to the actuated position drives the thrust linkin a linear manner.

The trigger mechanisms described herein provide mechanical advantages byincreasing the length of the firing stroke of the surgical instrumentwhile reducing the degree of movement of the trigger associated with thetrigger mechanism. The trigger mechanism also reduces the forcesrequired to actuate the trigger thereby enhancing usability andminimizing operator fatigue.

Other features of the present disclosure will be appreciated from thefollowing description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the presently disclosed trigger mechanisms foruse with a surgical instrument are described herein below with referenceto the drawings, wherein:

FIG. 1 is a perspective view of a surgical stapling instrument with atrigger mechanism in accordance with one exemplary embodiment of thepresent disclosure;

FIG. 2 is an exploded perspective view of the handle of the staplinginstrument;

FIG. 3 is a side elevation view illustrating the thrust link of thetrigger mechanism in engagement with the thrust member and the triggerin an initial position;

FIG. 4 is a side elevation view similar to the view of FIG. 3 with thetrigger in an actuated position and the thrust link driving the thrustmember to control operation of the end effector of the staplinginstrument;

FIG. 5 is an exploded perspective view of the handle and triggermechanism in accordance with another exemplary embodiment of the presentdisclosure;

FIG. 6 is a side elevation view of the thrust link of the triggermechanism of FIG. 5;

FIG. 7 is a side elevation view illustrating the thrust link of thetrigger mechanism of FIG. 5 in engagement with the thrust member and thetrigger in an initial position;

FIG. 8 is a side elevation view similar to the view of FIG. 7 with thetrigger in an actuated position and the thrust link driving the thrustmember to control operation of the end effector of the staplinginstrument;

FIG. 9 is an exploded perspective view of the handle and triggermechanism in accordance with another exemplary embodiment of the presentdisclosure;

FIG. 10 is a side elevation view of the thrust link of the triggermechanism of FIG. 9;

FIG. 11 is a side elevation view illustrating the thrust link of thetrigger mechanism of FIG. 9 in engagement with the thrust member and thetrigger in an initial position;

FIG. 12 is a side elevation view similar to the view of FIG. 11 with thetrigger in a partial actuated position during a first stage oflongitudinal movement of the thrust member; and

FIG. 13 is a side elevation view similar to the view of FIG. 12 with thetrigger in a fully actuated position and the thrust link driving thethrust member through a second stage of longitudinal movement to controloperation of the end effector of the stapling instrument.

DETAILED DESCRIPTION

The presently disclosed trigger mechanisms for use with a surgicalinstrument will now be described in detail with reference to thedrawings in which like reference numerals designate identical orcorresponding elements in each of the several views. In thisdescription, the term “proximal” is used generally to refer to thatportion of the instrument that is closer to a clinician, while the term“distal” is used generally to refer to that portion of the instrumentthat is farther from the clinician. In addition, the term clinician isused generally to refer to medical personnel including doctors, nurses,and support personnel.

The exemplary surgical instrument is a stapling instrument including ahandle, an elongate member, and an end effector coupled to the elongatemember. The end effector may include a staple cartridge and an anvil. Atleast one manually actuated trigger is mounted to the handle and isadapted to approximate the staple cartridge and the anvil to clamptissue therebetween and to actuate the firing mechanism to deliver thestaples through the tissue for crimping against the anvil and/or delivera knife to sever tissue between the applied staples. The trigger iscoupled to a linkage system which reduces the forces required to firethe staples and advance the knife.

Although the following discussion will focus on the use of the triggermechanism in connection with a surgical stapling instrument, the triggermechanism may be utilized in any instrument where a trigger ismechanically actuated to drive a drive member to control operation of anend effector. Examples of such instruments include biopsy instruments,forceps, graspers, etc.

Referring to FIGS. 1-2, the stapling instrument incorporating thetrigger mechanism of the present disclosure is illustrated and showngenerally as stapling instrument 10. The stapling instrument 10 includesa handle 12 having a handle frame 14 defining a grip 16, an elongatemember 18 extending from the handle frame 14, and an end effector 20coupled to the elongate member 18. A trigger mechanism 22 including atrigger 24 is mounted to the handle frame 14 and is adapted to pivotbetween initial and actuated positions to control operation of the endeffector 20. The end effector 20 includes a staple cartridge 28 housinga plurality of staples (not shown) and an anvil 30 for crimping thestaples ejected from the staple cartridge 28. The stapling instrument 10shares common features with the stapling instrument disclosed incommonly assigned U.S. Pat. No. 6,817,508, the entire contents of whichare incorporated by reference herein.

In the following description, only the functioning of the triggermechanism to drive the staples from the staple cartridge 28 of the endeffector 20 will be discussed. Details of the approximation mechanismfor approximating the staple cartridge 28 and the anvil 30 may beascertained by reference to the aforementioned U.S. Pat. No. 6,817,508.

Referring to FIGS. 2-3, the trigger 24 is mounted to the handle frame 14about pivot mount 32 which is coupled to the handle frame 14 throughconventional methodologies. A thrust link 34 is coupled to the trigger24 via reception of a thrust link pin 36 extending through openings 38of the trigger 24 and received within an aperture 40 of the thrust link34. The thrust link 34 defines a forward end 42 which is couplable to athrust member 44 extending through the elongate member 18. Inembodiments, the thrust member 44 may define a rear notch 46 whichreceives the forward end 42 of the thrust link 34 to couple the thrustlink 34 with the thrust member 44. A torsion spring 48 is positionedabout the pivot mount 32 of the trigger 24 to normally bias the thrustlink 34 upwardly in position to couple with the thrust member 44. Thethrust member 44 is configured for longitudinal movement to controloperation of the end effector 20 upon actuation of the trigger 24 andmovement of the thrust link 34.

In embodiments, the thrust link 34, the torsion spring 48, and thethrust member 44 are cooperatively configured to maintain the thrustlink 34 at a predetermined angle “a” with respect to the longitudinalhandle axis “k” during movement of the thrust member 44 through acomplete firing stroke. The angle “a” may range between about 1° toabout 30° relative to the longitudinal handle axis “k”. With thisarrangement, the thrust link 34 does not pivot relative to thelongitudinal handle axis “k”, which, in effect, causes direct linearmovement of the thrust link 34 and the thrust member 44 during pivotingmovement of the trigger 24 from the initial position of FIG. 3 to theactuated position of FIG. 4. Otherwise stated, there is a direct linearrelationship of the travel distance of the thrust link 34 and the thrustmember 44 relative to the pivotal movement of the trigger 24.Consequently, the length of the firing stroke of the thrust member 44 isincreased while the degree of pivotal movement of the trigger 24required to effectuate the firing stroke to deploy the staples from thestaple cartridge 28 and/or advance the knife is decreased therebyenhancing the mechanical advantage of the trigger mechanism 22 relativeto conventional mechanisms.

Referring now to FIGS. 5-8, another exemplary embodiment of the triggermechanism of the present disclosure is illustrated. This embodiment issubstantially similar to the embodiment of FIGS. 1-4 and reference ismade to the prior discussion for a description of like components.However, in accordance with this embodiment, the thrust link 50 definesan elongated slot 52, e.g., elongated along the longitudinal handle axis“k”, which accommodates the thrust link pin 36. In the initial positionof the trigger 24 depicted in FIG. 7, the thrust link pin 36 ispositioned within the distal end 52 d (FIG. 6) of the elongated linkslot 52. Upon pivotal movement of the trigger 24 to the actuatedposition of FIG. 8, the thrust link 50 slightly pivots about the thrustbar link 36 to initially drive the thrust member 44. Continued pivotalmovement of the trigger 24 causes the thrust link pin 36 to traverse theelongated slot 52 of the thrust link 50 and engage the proximal end 52 p(FIG. 6) of the elongated slot 52 to move the thrust link 50 in asubstantially linear manner. Thus, the length of the firing stroke ofthe thrust member 44 is increased while the degree of pivotal movementof the trigger 24 to the actuated position is minimized. In addition,the thrust link 50 includes a rear portion 50 a and an offset forwardportion 50 b offset relative to the proximal portion 50 a at an obliqueangle “a” ranging from, e.g., between about 5° and 30°. (FIG. 6) Thisoffset arrangement of the forward portion 50 b coupled with the biasingeffect of the torsion spring 48 ensures that the forward end 54 of thethrust link 50 remains engaged or received within the rear notch 46 ofthe thrust member 44 during movement of the trigger 24 from the initialposition to the actuated position.

Referring now to FIGS. 9-11, another exemplary embodiment of the triggermechanism of the present disclosure is illustrated. This embodiment issubstantially similar to the embodiment of FIGS. 5-8 and reference ismade to the prior discussion for a description of like components.However, in accordance with this embodiment, the handle frame 100includes an internal guide member 102 disposed about midway through thehandle frame 100. The guide member 102 has a horizontal surfacecomponent 104 in general parallel relation with the longitudinal handleaxis “k” and an angled surface component 106 in oblique relation to thelongitudinal axis “k”. A thrust link 108 is coupled to the trigger 24and has a forward drive cam 110 and a guide cam 112 depending outwardlyfrom an intermediate segment of the thrust link 108. The forward drivecam 110 couples with the thrust member 44. The guide cam 112 isengageable with the guide member 102, specifically, the horizontalsurface and angled surface components 104, 106 of the guide member 102during pivotal movement of the trigger 24.

The thrust member 44 includes rear notch 46 and a thrust bar arm 114depending downwardly from the rear notch 46. In the initial position ofthe trigger 24 depicted in FIG. 11, the forward drive cam 110 of thethrust link 108 is at least partially accommodated within the rear notch46 of the thrust member 44 and the guide cam 112 is in engagement withthe guide member 102, e.g., adjacent the intersection of the horizontalsurface component 104 and the angled surface component 106. Uponmovement of the trigger 24 to the partial actuated position of FIG. 12,the guide cam 112 traverses the angled surface component 106 of theguide member 102 causing the thrust link 108 to pivot about the thrustlink pin 36 and also cause the forward drive cam 110 of the thrust link108 to traverse the thrust bar arm 114 of the thrust member 44 therebyadvancing the thrust member 44 through a first stage of longitudinalmovement. Upon movement of the trigger 24 to the fully actuated positionof FIG. 13, the guide cam 112 is released from the guide member 102 suchthat pivotal movement of the thrust link 108 about the thrust link pin36 is discontinued, and the thrust link 108 is advanced in a linearmanner to drive the thrust bar arm 114 and the thrust member 44corresponding to a second stage of longitudinal movement of the thrustmember 44. The extended characteristic of the thrust bar arm 114provides an increased length of the firing stroke (i.e., including thefirst and second stages of longitudinal movement of the thrust member44) for the same angular rotation of the trigger 24 to further advancethe thrust member 44 and effect operation of the end effector 20.

Persons skilled in the art will understand that the devices and methodsspecifically described herein and illustrated in the accompanyingdrawings are non-limiting exemplary embodiments. It is envisioned thatthe elements and features illustrated or described in connection withone exemplary embodiment may be combined with the elements and featuresof another without departing from the scope of the present disclosure.As well, one skilled in the art will appreciate further features andadvantages of the disclosure based on the above-described embodiments.Accordingly, the disclosure is not to be limited by what has beenparticularly shown and described, except as indicated by the appendedclaims.

1. A surgical instrument, comprising: a handle including a handle framedefining a longitudinal handle axis; an elongate member extending fromthe handle frame; an end effector coupled to the elongate member; athrust member extending through the elongate member and coupled to theend effector, the thrust member configured for longitudinal movement tocontrol operation of the end effector; and a trigger mechanismincluding: a trigger pivotally mounted to the handle frame andconfigured for movement between an initial position and an actuatedposition; and a thrust link coupled to the trigger and operativelyengageable with the thrust member, the thrust link extending relative tothe longitudinal axis at a fixed link angle, the thrust linklongitudinally advanceable while maintaining the fixed link angle uponmovement of the trigger from the initial position to the actuatedposition to cause corresponding advancing movement of the thrust memberand operation of the end effector.
 2. The surgical instrument accordingto claim 1, wherein the fixed link angle ranges from 1° to 30°.
 3. Asurgical instrument, comprising: a handle including a handle framedefining a longitudinal handle axis; an elongate member extending fromthe handle frame; an end effector coupled to the elongate member; athrust member extending through the elongate member and coupled to theend effector, the thrust member configured for longitudinal movement tocontrol operation of the end effector; and a trigger mechanismincluding: a trigger pivotally mounted to the handle frame andconfigured for movement between an initial position and an actuatedposition; and a thrust link coupled to the trigger and operativelyengageable with the thrust member, the thrust link defining an elongatedslot for reception of a thrust link pin mounted to the trigger, thethrust link configured to pivot about the thrust link pin and tolongitudinally advance upon movement of the trigger from the initialposition to the actuated position to cause corresponding advancingmovement of the thrust member to operate the end effector.
 4. Thesurgical instrument according to claim 3, wherein the elongated slot ofthe thrust link defines a proximal end and a distal end, the thrust linkbeing positioned adjacent the distal end of the elongated slot when inthe initial position of the trigger and configured to traverse theelongated slot for positioning adjacent the proximal end of theelongated slot upon movement of the trigger to the actuated position. 5.The surgical instrument according to claim 3, wherein the thrust linkincludes a rear portion and a forward portion that are offset relativeto one another at an angle.
 6. The surgical instrument according toclaim 5, wherein the angle ranges from between about 5 degrees and about30 degrees.
 7. The surgical instrument according to claim 6, furthercomprising a torsion spring that maintains the forward portion of thethrust link engaged with the thrust member.
 8. The surgical instrumentaccording to claim 7, wherein the thrust member defines a rear notchthat receives the forward portion of the thrust link.
 9. The surgicalinstrument according to claim 8, wherein the torsion spring urges theforward portion of the thrust link within the rear notch of the thrustmember when the trigger moves from the initial position to the actuatedposition.
 10. The surgical instrument according to claim 9, wherein thetorsion spring is mounted to the trigger.
 11. A surgical instrument,comprising: a guide member with an internal guide surface; an elongatemember supporting an end effector; a thrust member configured to controloperation of the end effector, the thrust member defining a thrust bararm; and a trigger mechanism, including: a trigger configured to moverelative to the end effector between an initial position and an actuatedposition; and a thrust link coupled to the trigger, the thrust linkhaving a forward drive cam engageable with the thrust bar arm of thethrust member and a guide cam engageable with the internal guide surfaceof the guide member, the thrust link configured to move upon movement ofthe trigger from the initial position to the actuated position throughmovement of the guide cam along the internal guide surface of the guidemember to cause corresponding movement of the forward drive cam of thethrust link along the thrust bar arm of the thrust member to causeadvancing movement of the thrust member for operating the end effector.12. The surgical instrument according to claim 11, wherein the internalguide surface of the internal guide member is arranged in obliquerelation to a longitudinal axis of the surgical instrument.
 13. Thesurgical instrument according to claim 12, wherein the trigger isoperable between the initial position, the actuated position, and apartial actuated position intermediate the initial and actuatedpositions.
 14. The surgical instrument according to claim 13, whereinthe guide member is configured such that the internal guide surface isreleased relative to the guide cam of the thrust link upon movement ofthe trigger beyond the partial actuated position whereby continuedmovement of the trigger to the actuated position drives the thrust linkin a linear manner.
 15. The surgical instrument according to claim 11,wherein the guide member is supported by a handle frame.
 16. Thesurgical instrument according to claim 15, wherein the elongate memberextends from the handle frame.
 17. The surgical instrument according toclaim 16, wherein the thrust member extends through the elongate member.18. The surgical instrument according to claim 17, wherein the thrustmember is coupled to the end effector.
 19. The surgical instrumentaccording to claim 11, wherein the thrust link pivots upon movement ofthe trigger.
 20. The surgical instrument according to claim 11, furthercomprising a torsion spring that is supported on the trigger andpositioned to engage with the thrust link.